The present invention relates to automobile anti theft devices and alarms. In particular the invention relates to an easily installed alarm for an automobile that is tamper resistant.
The assignee of the present invention presently markets an automobile anti-theft device under the trademark ON GUARD, which is described in U.S. Pat. No. 5,163,309. This device is designed to attach to the steering wheel of an automobile and extend over the dash board in close proximity to the dashboard, thereby preventing the wheel from being turned. The position of the device makes its presence easily seen by a would-be car thief, thus discouraging the thief from attempting to steal that particular automobile.
Another commonly used anti-theft device is an alarm system. There are many known auto alarms, which respond to a variety of events, including electrical system transients arising out of activation of interior, trunk or under-hood lights; vibration sensing devices; ultrasonic devices that sense opening of a door; etc. Most known alarm devices require installation and connection to the electrical system of an automobile. Installation and connection are complicated by the requirement that the device be secured to the automobile with sufficient mechanical attachment to prevent the alarm device from being rapidly removed and discarded as a car thief drives away.
A portable alarm unit that requires no installation is presently available and consists of an electronic unit with a connector to be plugged into the outlet of the automobile's cigarette lighter. This unit has not achieved much success, even though it is inexpensive and requires no installation, because it can easily be removed and discarded by a thief.
There have also been proposals to provide tampering alarms as part of mechanical security devices of the type that attach to automobile controls, such as the steering wheel. Such devices do not provide complete protection against vehicle entry, for example to steal the contents or parts of the vehicle, and are susceptible to tampering to disable the alarm because of the availability of the electronic portion.
It is therefore an object of the present invention to provide a combined security device and alarm unit that attaches securely to a vehicle, is tamper resistant and requires no permanent installation.